Originating Olympic coverage always encourages pushing the technology envelope, but not enough to risk the shot. So while new technologies are often tried, such trials may actually be larger implementations of trusted systems. That wasn't the case with one aspect of this year's Winter Olympics broadcasts in Canada.
Mobile coverage
One of the toughest things for broadcasters to cover is a moving event. One familiar mobile event is the marathon. Here, the length is 26.2mi. Sure, you could use a helicopter, but that is an extremely expensive platform, and there's no possibility of a first-person look at the runners from 2000ft.
A typical solution is the motorcycle. Here, a driver and camera person move in tandem with the runners. One benefit is the opportunity for excellent close-ups. The key to success is a reliable RF relay system as the camera moves throughout the marathon path. Such solutions can be expensive and complex.
This was the dilemma facing Canadian broadcaster CTV. The network wanted to provide viewers with continuous live coverage of torch carriers as they ran through 1000 Canadian communities to the site of the Olympic Games in Vancouver. The problem was now to remain close enough to the runners to get good images all the while doing so over a multimile course.
The broadcaster's solution was supplied by a startup company called Dejero from Waterloo, Canada. With Dejero's portable broadcast platform, CTV was able to provide live and online broadcasts of up to 10 hours per day for 86 of the 106 days of the torch relay. The system works with existing cell phone service; Wi-Fi connections; satellite data services, such as Inmarsat's BGAN network; or next-generation wireless links, such as WiMAX and HSPA+ networks.
The system identifies available cell phone bandwidth, encodes the video to that bit rate and distributes outgoing video data across multiple cell phone connections to deliver a live online and on-air signal. (See Figure 1.) It combines off-the-shelf components with proprietary software to manage data throughput and match it to available wireless channels.
“The system is smart enough to figure out available bandwidth based on the environment it is in,” says company CTO Bogdan Frusina. Upon startup, the company's ENG platform scans available wireless connections and sets a target bit rate for its MPEG-4 H.264 encoder based on available bandwidth. In a newsgathering environment, the device typically uses 2Mb/s to deliver live SD feeds with less than one second of talk-back latency. When the system was used to cover the torch relay, the system was configured for 1.5Mb/s.
Engineers recognize that using wireless networks for live links may result in unpredictability because cellular networks do not guarantee bandwidth. The Dejero technology solves the high bandwidth requirement of video by splitting the data across multiple wireless channels — any one of which can vary dynamically based on the carrier. On the receive side, the system's server reassembles incoming data from the multiple wireless channels and delivers the reconfigured video.
For the CTV Olympic torch relay, the Canadian broadcaster mounted a robotic camera in a protective Plexiglas enclosure and affixed it to mobile home. An HD-SDI signal from the camera fed the transmitter and was sent via various carriers back to CTV control rooms along the route. The Web-addressable transmitter was configured over the Internet to direct its feeds to multiple servers at the various CTV ENG receive sites along the torch relay path.
The Olympic broadcasts involved only SD video. However, according to company officials, the system can also support HD video, albeit with additional latency. The firm says it will be able to achieve one-second talk-back latency over next-generation cell phone networks.
Is your microphone on an endangered species list?
Many users of 700MHz-band wireless microphones received a nasty surprise early this year when the FCC released a list of microphones that will be prohibited from use after June 12, 2010. The list contains the model numbers — manufacturer by manufacturer — of banned models and whether they can be upgraded to meet the new requirements. Under the FCC's order, users of the prohibited models have only a couple of months to switch to legal models of wireless devices or cease operation.
This shouldn't come as a surprise. The FCC's ruling was part of a national shift on the deployment of bandwidth, which is now in “crisis” according to its chairman, because of increased use by mobile telephones and wireless computers. The commission said the wireless microphone transition is necessary to make spectrum in the 700MHz band available for use by next-generation wireless services for consumers and public safety agencies.
Wireless microphones, in-ear monitors and other wireless devices will continue to be permitted in the remaining UHF TV band (470MHz to 698MHz). Existing 700MHz equipment should be replaced with systems operating in that range or in other parts of the spectrum.
Many sporting groups and others hoped the commission would allow them to use some part of the spectrum and had argued their use of it would not interfere with new devices. Their arguments did not deter the FCC. Much of the spectrum used by wireless microphones was auctioned to wireless carriers for about $20 billion.
The list of banned devices can be viewed at www.fcc.gov/cgb/wirelessmicrophones/manufacturers.html.
Phil Kurz writes Broadcast Engineering's “News Technology Update” e-newsletter.
